100
Development of an
Acousto-Optic Tunable Filter Based Imaging Radiometer for Solar Spectral
Measurement--Brimrose Corporation of America, 5024 Campbell Boulevard, Suite
E, Baltimore, MD 21236-4968;
410-931-7200, www.brimrose.com
Dr. Jolanta I. Rosemeier,
Principal Investigator,
Mrs. Diane C. Murray, Business
Official,
DOE Grant No.
DE-FG02-02ER83374
Amount:
$750,000
Existing devices for collecting
atmospheric radiation measurements have many limitations to the performance and
accuracy of information derived from the acquired data.
For example, some devices can obtain information only at certain fixed
wavelengths, some have low spectral resolution, and some have moving components,
subject to vibration or shock, that require frequent calibration. This
project will develop an acousto-optic tunable filter (AOTF), as the dispersive
element in the radiometer, which will reduce contamination error, provide higher
resolution, and perform instantaneous measurement at any wavelength—all in a
device with no moving parts. Phase
I designed and fabricated two dual-channel AOTFs that operated over the
wavelength range from 360nm to 2500nm; demonstrated apodization techniques to
minimize the sidelobes of the AOTF; and measured the diffraction efficiency and
spectral resolution at various wavelengths. Preliminary
imaging, including solar imaging, in the visible and infrared regions (360nm to
1100nm) was demonstrated. Phase
II will focus on developing two radiometer systems: a
complete imaging radiometer system that uses silicon CCD arrays in the
wavelength range from 360–1100nm, and a radiometer that uses a dual
wavelength detector in the wavelength range
from 360–2500nm. Performance will be
optimized by increasing the spectral resolution, increasing out-of-band
rejection, and optimizing the apodization techniques.
Commercial
Applications and Other Benefits as described by awardee: The
device should increase our understanding of meteorological, chemical,
physical, and thermodynamic processes and phenomena in the atmosphere.